Servers can be prioritized assigning a weight. A server that has been given
a weight of two will get twice as many requests as a server that has been
given the default weight of one. Prioritization can be handy in heterogenous
environments. For example, you may want to assign more requests to
a powerful machine than to a less powerful. Or, you may have configured
servers that are close or far from the client, thus expose different latencies.